1. Field of the Invention
The present invention relates to a thawing indication marker to be used on a frozen food, in particular, to a thawing indication marker for a frozen food, capable of easily judging whether or not the frozen food has been thawed.
2. Description of the Related Art
Conventionally, most of frozen foods including fishery products are frozen at a low temperature of -10.degree. C. to -40.degree. C. with various kinds of freezing equipment so that the freshness of the frozen foods can be maintained for a long time until the foods are thawed.
However, a problem may arise in that these frozen foods, which should be treated in a temperature not more than 0.degree. C., are treated in an atmosphere (environment) over 0.degree. C. due to mix-up of taking frozen foods for cold-storage goods, etc., and being left without recognizing so that the frozen foods are thawed and the freshness thereof is ruined to lose the merchandise value. That is, the frozen foods, which have been thawed cannot regain the initial freshness even though they are frozen again, and thus the merchandise value of once thawed frozen foods declines.
A judging means capable of easily and accurately indicating the freshness of frozen foods, that is, whether or not the frozen foods are maintained in the initial frozen state, and whether or not the frozen foods have been thawed in the intermediate state, has been called for.